JPH0465784A - Character segmenting circuit - Google Patents

Abstract

PURPOSE:To make it possible to separate characters even when these characters are superposed on a projected screen by dividing a character area decided as continued characters into previously set small areas and separating the continued characters by detecting whether the divided small areas contact with each other or not. CONSTITUTION:The character segmenting circuit 1 segments characters by a conventional projection method and a continued character detecting circuit 2 decides a character in a character area as continued characters when at least one of X-axis direction length and Y-axis direction length exceeds a previously set prescribed value. A range division projecting circuit 3 divides the range of the continued characters detected by the circuit 2 into the previously set small areas and executes character segmentation based upon the projection method and a continued character separating circuit 4 sorts each small area group in which characters contact with each other and separates the continued characters. Thereby even when respective characters are superposed on a projection screen, these characters can be separated from each other and a character recognition rate can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a character cutting circuit, and more particularly to a cutting method for optically read free handwritten characters.

BACKGROUND ART Conventionally, as shown in FIGS. 12 to 16, this type of character extraction method has
) (see Figure 12) exists in a two-dimensional space represented by two coordinates, the X-axis and the Y-axis, and by irradiating this image with a parallel ray perpendicular to the Y-axis, A shadow YO and a shadow Y1 are obtained.

Among the end points of these shadows YO and Yl, the coordinate origin (
Let S be the one closer to the coordinate origin (0,0), and L be the one farther from the coordinate origin (0,0), then the shadow YO and the shadow Yl
Each end point is YSO, YLO, YSI, YLI respectively
(See Figure 13).

In addition, the end points YLO, Y of the shadow YO and the shadow Y1 are added to this image.
When a parallel ray perpendicular to the X-axis is irradiated from the LI side, the shadow YO
And a shadow XO and a shadow Xl are obtained on a line perpendicular to the Y axis from the end points yso and yst of the shadow yi.

Among the end points of these shadows XO and Xl, the coordinate origin (
0, O) is represented by S, and the one far from the coordinate origin (0, 0) is represented by L, then the shadow XO and the shadow X1
The end points of are respectively XSO, XLO and xst, xi,
t (see Figure 14).

XSO, XLO, YSO obtained as above.

The positions in the two-dimensional space expressed by the four coordinates YLO, XSI, XLI, YSl, and YLI are (XSo, YSO), (ISO, YLO), and (XLO), respectively.
, YSO), (XLO, YLO) and (XSI, Y
SI), (X St.

Y Ll), (XLI, YSI), (XLI, YL
I), and each rectangle connecting these points is 1
1 character. m (see Figure 15).

Hereinafter, the shadows Xo, xi, yo obtained by the method described above, that is, by irradiating parallel rays perpendicular to the X and Y axes, will be explained.
, yt is simply called a projection method.

In conventional character extraction methods like this, the projection method is the basic method, so when characters overlap in projection ("east" and "above" in Figure 16), those characters are converted into normal characters. It could not be extracted as a single character, which was one of the causes of a decline in character recognition rate.

Purpose of the Invention The present invention has been made in order to eliminate the problems of the conventional ones as described above.Even if characters overlap on the projection, those characters can be separated, thereby improving the character recognition rate. The purpose of this invention is to provide a character extraction circuit that can perform the following functions.

Structure of the Invention The character cutting circuit according to the present invention is a character cutting circuit for a character identification device that identifies each character of a character string on a paper sheet, and is characterized in that the character cutting circuit is a character cutting circuit for a character recognition device that identifies each character in a character string on a paper sheet, and is characterized in that a setting means for setting a character area; and a setting means for setting a character area when at least one of the length in the X-axis direction and the length in the Y-axis direction of the character area set by the setting means exceeds a predetermined value. determining means for determining characters within an area to be continuation characters; dividing means for dividing the character area determined to be continuation characters by the determining means into preset small areas; The present invention is characterized by further comprising a separating means for separating the continuous characters depending on whether or not the small areas are in contact with each other.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. In the figure, a character cutout circuit 1 cuts out characters in rows I, ) by a conventional projection method, and a continuation C7 detection circuit 2 detects a continuation character from among the characters cut out by the character cutout circuit 1.

Here, a character in which two or more consecutive characters are cut out as one character is simply referred to as a character.

The range division projection circuit 3 divides the range of the ``Zoku'' character detected by the ``Zoku'' detection circuit 2 and performs cutting again using the projection method. Classify them as overlapping or touching (continuous), and then separate the characters.

FIGS. 2 to 11 are diagrams showing a character cutting operation according to an embodiment of the present invention. In these figures, FIG. 2 shows the extraction result of the character extraction circuit 1 of FIG. 1, FIGS. 3 to 6 show the processing operation of the range division projection circuit 3 of FIG. 1, and FIG. It shows the processing results of the range division projection circuit 3 of FIG. 1.

Further, FIG. 8 shows the processing operation of the character separation circuit 4, which is a continuation of FIG. 1, and FIG. 9 shows the result of character segmentation according to an embodiment of the present invention.

Furthermore, FIGS. 10 and 11 show examples of cutting out horizontally written characters according to an embodiment of the present invention.

For example, when the address of the mail is "Higashiueno, Taito-ku", this address is determined by the character cutting circuit 1: "Taichi" is the letter a, "Higashi" is the letter B, "ku" is the letter C1, "Higashijo" is the letter d1. "
field' is cut out as the letter e (see Figure 2), and the letter a-
A case where c and e are cut out one character at a time, whereas character d is cut out with two characters as one character will be explained.

The characters a - e cut out by the character cutting circuit 1 are sent to the 7-7 detection circuit 2, and the 7-detection circuit 2 detects the character 2-7 from among them.

Characters a to e cut out by the character cutting circuit 1 are XS and XL, respectively, indicating the positions of four points on the coordinate space.

It is expressed by four values YS and YL, and the width W and height H of the rectangle (character cutting range) expressed by these four values.
can be calculated using the following formula.

Width W - XL - 2) Based on the width W and height H determined by the formula, it is determined whether the characters a - e are continuation characters or not.

When the address of a postal item is written vertically, the Zoku wa 7 detection circuit 2 determines that the group is a Zoku wa character if the following formula is satisfied.

Height H/Width W≧Set value A・・・・・・・・・(3) Width W
≧Setting value B ・・・・・・・・・(4) In this example, as a result of investigating the characters on actual mail, the setting value A-2
-■, setting value B - 8 ms, but the optimum values are selected for the setting values A and B depending on regional characteristics and differences in vertical or horizontal writing.

Therefore, since character d satisfies the above equations (3) and (4) among the characters a - e extracted by character extraction circuit 1, the continuation is 7 detection circuit 2 selects the character d as a character in the range. It is output to the divisional projection circuit 3.

On the other hand, if, for example, the pattern f shown in FIG. The shadow Y of f is divided into four parts like the range A-D.

YB, YC, YD) [see Figure 5(a)], range A-D
Project each onto the X axis (shadow X^, XB,
C, XD) [see Figures 5(b) to (e)].

These shadows XA, YA and shadow XB, YB and shadow XC.

Using YC and the shadows XD and YD, the range division projection circuit 3 can cut out the pattern f into small areas Al, Bl, CI, and Di (see FIG. 6).

The range division projection circuit 3 performs the above processing on the character d detected as a character d by the 7 detection circuit 2, and cuts out the character d in preset small area units (see FIG. 7).
, and outputs the extraction result to the sub-character separation circuit 4.

In this example, the shadow Y of the character d is divided into 0.80 units to obtain the cutting results shown in Figure 7, but the values of small areas may vary due to regional characteristics and differences in vertical or horizontal writing. The optimal value is selected.

A continuous separation circuit 4 classifies the cutting results of the range division projection circuit 3 on the condition of overlap or contact (continuity).
The character d is detected as a character by the 7 detection circuit 2.
Perform the separation.

When the cutout results of the range division projection circuit 3 are classified according to the conditions of overlap or contact (continuity), the character d is classified into block group I (r east) and block group (See Figure 8), these block groups 1. It becomes possible to separate the character d, which is detected as a continuation character, into characters dl and d2 (see FIG. 9).

Here, the Zoku-sha separation circuit 4 calculates the cutout results of the small areas by the range division projection circuit 3 to determine whether they overlap or touch (continuity).
Since the classification is based on the conditions of
or katakana "ru", etc., each block group classified according to the conditions of overlap or contact (continuity) is sent to a recognition unit (not shown), and the recognition unit identifies adjacent block groups and Character recognition is performed by determining from a group of blocks contained within the area of one character.

Further, in the detection circuit 2, when the address of the mail piece is written horizontally, the width W and height H are calculated using the above equations (1) and (2), and the width W and height H are calculated using the above equations (1) and (2). If satisfies the following formula, the group is determined to be a continuation.

Width W/Height H≧Setting value A (5) Height H≧Setting value B (6) 10th
As shown in the figure, when characters g-k are cut out from a postal item whose address is written horizontally by the character cutting circuit 1, the detection circuit 2 calculates the character j by the above equations (5) and (6). Since the character j is satisfied, the character j is outputted to the range division projection circuit 3 as a letter ``Zoku'', and the cutout result as shown in FIG. 11 can be obtained by the range division projection circuit 3 and the letter separation circuit 4. In other words, the continuation converts the character j detected as a character to character j
It becomes possible to separate into l and j2.

In this way, from among the characters a-e and g- cut out by the conventional projection method by the character cutting circuit 1, there are 7 detection circuits 2.
The range of the detected Zokuha character is divided into small area units set in advance by the range division projection circuit 3, and the small area units are extracted. By classifying characters based on (continuity) and separating characters, even if the characters overlap on the projection, it is possible to separate the characters, and it is possible to separate the characters even if they overlap on the projection. The recognition rate can be improved.

Detailed Description of the Invention According to the present invention, at least one of the length in the X-axis direction and the length in the Y-axis direction of the character area set by the projection of the character on the X-axis and the projection on the Y-axis. exceeds a predetermined value, the character in the character area is determined to be a continuation character, and the character area of the continuation character is divided into predetermined small areas and a group of small areas that are in contact with each other. By separating continuation characters by classifying them, it is possible to separate the characters even if they overlap on the projection, and this has the effect of improving the character recognition rate. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram showing the extraction result of the character extraction circuit of FIG. 1,
3 to 6 are diagrams showing the processing operation of the range division projection circuit of FIG. 1, FIG. 7 is a diagram showing the processing results of the range division projection circuit of FIG. The following are diagrams showing the processing operation of the character separation circuit, FIG. 9 is a diagram showing character extraction results according to an embodiment of the present invention, and FIGS. 1110 and 11 are examples of horizontally written character extraction according to an embodiment of the present invention. Figure 1 showing
2 to 16 are diagrams showing processing operations in the conventional example. Explanation of symbols of main parts 1...Character cutting circuit 2...Continued 7Detection circuit 3...Range division projection circuit 4...Continued character separation circuit

Claims (1)

[Claims] (1) A character cutting circuit of a character identification device for identifying each character of a character string on a paper sheet, comprising a setting means for setting a character area by projecting the character on the X-axis and on the Y-axis; , when at least one of the length in the X-axis direction and the length in the Y-axis direction of the character area set by the setting means exceeds a predetermined value set in advance, the characters in the character area are made into continuation characters. A determining means for determining, a dividing means for dividing the character area determined to be the continuation character by the determining means into preset small areas, and whether the small areas divided by the dividing means are in contact with each other. A character cutting circuit characterized in that it is provided with a separating means for separating the continuation characters depending on whether the characters are continuous or not.